Method of making gold inlays.



US ALEXANDER THURSTON, OF CHICAGO, ILLINOES.

METHOD DE MAKENG GOLD INLAYS.

(ZZZ iii/ win it may concern:

Be it known that 1, Famous TnURsToN, citizen of the United States, residing at i in the county of Cook and State of have invented a certain new and hlethods of Making clear, concise, and exact description.

ie method making metal objects for dental 1' other work which shall be accurate and t the same time rapid and economical.

further object is to mold the use of special apparatus in making inlays of gold or other metal. The method described herein while developed primarily for use with gold has been applied successfully in making platinum and silver inlays. An essential and the first step in the process is the preparation of metal sponge of a high melting point. This sponge may be prepared in any quantity desired and kept in readiness for dental or other operations.

preparing the gold sponge, moss fiber old or any preparation equally as spongy be used. The spongy gold is mixed may with

pared as follows: Mix a small quantity of 'cocoanut oil with, resin, sulhcient to make 'um that wi l not rate run when cool.

is done by heating the resin and add ing the oil in sullicient quantity. The gum t added to the gold by dipping there- 'lat instrument and carrying threads he stringy gum over the mat of sponge {old sulliciently close together so that when 'ielted the entire surface of the resulting ni.;ture will. be pretty well permeated with The tendency is to get too much gum gel l. The resulting gold mat is laced on asurit'ace which can be evenly and brought to a temperature where will sin l .e, wl ereupon the hcatis stopped. ei-e should be taken to prev nt the gold in any part becoming red hot as tlat will make it granular. The resulting sponge is slightly s icky even in the )resence of moisture and retains a considable degree of porosity, so that alter'polhing, the pores of the soonge are not comoleteiy closed. I

Fihile the preceding method or preparing the binder and sponge is the preferred method it will be obvious to those who have I)? i ulltml 1 Specification of Letters Pater t.

Application filed July 26,1911.

object of this invention is to provide a binder, which binder may be pre- Patented Dec. 26, lllllltl.

Serial No. 640,595.

had experience with gums and oils that a number of substances may be substituted for the resin, such as beeswax, parafin, shellac.

or other equivalents. Moreover, other oils than cocoanut oil may be used such as light cotton seed oil or any oil which is capable of. dissolving the gummy material used. in fact the particular binder used is not an essential feature of my invention, but any binding material may be used which will retain its porosity and which can be eliminated without destroying the form of the sponge. It has been found also, that, borax may he used with the resin or other gum. 'While this method was originally developed in conmotion with gold sponge, it has been found that the method may be applied to substances which are not metallic in their natur such as silica, it only being necessary that the material used as a base for the original sponge shall be somewhat retractory so that the binder may be driven off and the filling material fused into place without destroying the form of the article desired.

t will be seen also that wherever in the specification metal is referred to as being fused into the sponge. other material might be used as a tiller instead of metal, the only may not be necessary, but the inlay may be prepared follows: Oil the cavity and select a piece of treated spcnge gold in bull: several times larger than the space to be filled and with a burnisher force the cavity full and compact, leaving the cavity slightly over-full. If more sponge is used than necessary itmay be trimmed away with a warm instrument, while if more is required it may be applied since the sponge is slightly sticky as above mentioned. If the sponge is in clined to flake off, heat the instrument, dip in some light oil to prevent sticking and the piece may be pressed into position. To remove, heat a sharp pointed explorer and drive in the center ot the $001 with water and the gold will out in one piece. Coat the cavity surface of the filling with'casting investment taking care not to let any get on the surface in which the ex plorer is inserted. When the investment sets heat the instrument near the filling and it will easily remove without disturbing the "old. 1

b After having prepared the sponge to fit the cavity as described the prepared sponge is placed on an asbestos mat, cavity side down, in an electrical or gasolene oven or in the flame of a blow torch. Heat the piece gradually to drive off the gum, since if hastened at first the pieces will blister. Place on top of the filling metal clippings of lower karat to the quantity which the sponge will absorb without excess. A liquid surface when melted will indicate that the sponge is satisfied. The instant the pieces are seen to melt withdraw them for examination. As long as a rough surface is presented the sponge is still unsatisfied and more clippings are required.

In cases where walls of compound cavities and simple cavities are properly shaped, a matrix may not be necessary. However in cases where a matrix is thought to be advantageous proceed as follows: The cavity is prepared in the same way as for any in lay filling. To conserve gold the cavity if too deep may be partly filled with cement or other suitable material. The matrix may be made very satisfactorily of pure thin plate gold, for instance No. .002 SSTVG. In case of large fillings a piece of paper is trimmed to size for pattern and the gold plate cut to it. The gold plate is then placed over the cavity and pressed to place with a wet pellet of cotton. The gold is then removed and annealed and pressed into place a second time, it making no difference if the bottom of the gold tears. After thus preparing the matrix it is filled with sponge gold in the same manner as previously described in the case of a simple cavity, and the inlay prepared by melting in additional pieces of metal, also as previously described. If the cavity is in an occlusal surface have the patient bite in the gold the same as if taking a wax impression of the cavity for a casting. In this way an occlusion may be procured as correct as if a wax impression were made for a casting and with about an equal amount oftrouble. In case of a compound cavity an ivory matrix should be used as just described, disengaging the clamp when the bite is to be taken. lVhen complete remove the entire piece for firing.

The fillings with matrices do not require I investing, but after baking should have the sin-faces to be cemented slightly roughened by rolling over with a small bur. The cementing process is the same as any other inlay process and need not be described here. Bridges and gold plates maybe made in a manner similar to fillings, Pure gold matrices of thicker gold than for inlays are used. Since these pieces are of large size it is probable that they will need to be baked in the flame of a blow torch, since the avermanufacture of articles of 1ewelry for personal wear, or gold and silver dishes and similar articles.

Having thus described my invention,

what I claim as new and desire to secure by I Letters Patent is: I

1. The method of making metal articles which consists in preparing a porous metal said sponge metal to fill the pores thereof and to enable it to retain its original shape under pressure.

2. The method of making metal articles which consists in preparing a metal sponge and fusing into said sponge metal of the same character but of a lower melting point.

3. The method of making metallic sponge sponge of the shape desired, and fusing intofigo which consists in mixing metal particles or fibers with a semiliquid binder and subjecting the resulting mass to the action of heat.

4. The method of preparing metal sponge which consists in mixing spongy metal with a semiliquid binder and subjecting the resulting mass'to the action of heat.

The method of making a metallic sponge which consists in preparing a semiliquid binder by dissolving resin in cocoannt oil, adding said binder to spongy metal and subjecting the resulting mass to the action of heat.

6. The method of making gold. inlays which consists in mixing spongy gold with a semiliquid binder, subjecting the resulting mass to the action of heat to form a plastic, adhesive metal sponge, molding the said metallic sponge to the shape of the cavity to be filled and fusing into said sponge gold of a lower melting point than the first mentioned gold.

7. The method of making gold sponge which consists in mixing spongy gold with a binder and heating the resulting mass to a temperature below red heat.

8. The method of making metallic sponge which consists in preparing a binder by dissolving a wax-likematerial in a vegetable oil, and intimately mixing small pieces of metal with said binder.

9. The method of making metal articles which consists in preparing a metal sponge and fusing into said sponge other material of a lower melting point.

10. T he method of preparing gold sponge which consists in mixing sponge gold with a binder and heating the resulting mass to and adding t'used material to replace the binder in the pores of the sponge.

12. The method of making articles which consists in mlxmg small pieces of material with a destructible binder to form a sponge,

forming the sponge in the shape desired, heating the sponge to drive off the surplus binder, and adding fused metal to replace the binder in the pores of the sponge.

13. The method of making metallic sponge which consists in preparing a binder.

by dissolving a Wax-like material in an oil and intimately mixing small pieces of metal with said binder.

14. The method of making plastic me-. tallic sponge which consists in dissolving a solid component having the characteristic of being completely volatilizable by heat in a liquid solvent to form an adhesive binder, mixing said binder with small pieces of metal, and heating the resulting mixture to a ten'iperature below red heat to dispel the excess of solvent and to insure a complete mixing of metal and binder.

In witness whereof, I hereunto subscribe my name this twenty-second day of July A. 1)., 1911.

FREDUS ALEXANDER THURSTON.

\Vitnesses:

Avons'rus S. DENNISON, O. M. \Vnumcn. 

